In recent years, with regard to recovery of carbon dioxide, carbon dioxide recovery storage technique attracts attention as an effective measure against problem of global warming which is worried about in global scale. In particular, for thermal power plants and process exhaust gas, a method for recovering carbon dioxide using aqueous solution has been studied. For example, a carbon dioxide recovery device is known, which includes an absorption tower and a regeneration tower. The absorption tower generates rich solution by absorbing carbon dioxide-containing gas to absorbing solution. The regeneration tower disperses and separates the carbon dioxide with steam by heating the rich solution discharged from the absorption tower, and returns the generated lean solution back to the absorption tower.
However, in the conventional carbon dioxide recovery device, when carbon dioxide-containing gas is provided to the absorption tower at the start of operation, rapid heating occurs in the absorbing solution because of carbon dioxide absorption reaction, and there is a problem in that abnormally high temperature may damage the absorption tower equipment or may degrade the absorbing solution. This problem occurs not only at the start of operation but also when the carbon dioxide content in the exhaust gas rapidly increases.